1. Field of the Invention
This invention relates generally to cooling apparatus for marine propulsion system outdrive units, and more particularly to an improved multiport drive shower that does not require creating holes in the outdrive of the marine propulsion system.
2. Description of Related Art
Over the years there have been various attempts to cool marine propulsion systems. Cooling of marine propulsion systems is required to maintain proper operating temperatures of both the prime mover, such as an internal combustion engine, as well as the various power transfer systems used in marine propulsion systems, such as, for example, outdrives.
As the complexity of marine stern drive technology has developed, so has the need to keep the outdrive cool in a wider variety of operating conditions. U.S. Pat. No. 4,371,351 to Tousey describes a stern drive cooler that uses a conduit to carry water from below the water level of the vessel to a position over the stern drive. Such early cooling systems were able to direct cooling water only to the top of the stern drive, and were not capable of cooling the entire upper portion of the stern drive. In a stem drive, internal components such as gears, clutches and bearings produce heat. Under extreme operating conditions such as high RPMs, high torque levels, prolonged usage, and the like, the produced heat may become excessive. The detrimental effects to the outdrive can range from purely cosmetic to catastrophic failure if the heat begins to breakdown the drive oil used to lubricate the internal components of the stern drive. Although stern drive manufacturers have developed proprietary drive unit oils to help combat this heat induced breakdown, they have not been entirely successful in mitigating all of the effects of excessive heat in the outdrive.
Another example of an attempt to cool an outdrive of a stern drive device is U.S. Pat. No. 6,808,432 to Davis et al, and Assigned to Brunswick Corporation of Lake Forest, Ill. The entire disclosure of which is incorporated herein by reference.
The need to cool more than just the top of the outdrive led to the development of a multiport drive shower by Paul Kermis, as described in U.S. Pat. No. 6,241,566, the entire disclosure of which is incorporated herein by reference. While the multiport drive shower disclosed by Kermis in the '566 patent provided exceptional cooling ability, it continued to share one drawback common to all existing outdrive cooling devices. The technique used to mount the multiport drive shower to a stem drive involved creating holes through the anti-cavitation plate of the stern drive. This mounting technique is viewed by many to be too intrusive both cosmetically and structurally to the stern drive. In addition, the manufacturer has recently declared that piercing the protective coating on their current models of outdrives will void their corrosion warranty, thus voiding the manufacturer's warranty in many cases.
It is therefore an object of the present invention to provide a multiport drive shower that attaches to an outdrive without the need for creating holes in the outdrive, yet provide sufficient support to maintain the location and integrity of the pick-up port system. It is another object of the present invention to provide a multiport drive shower that efficiently takes water in using a ram effect through the use of softer and more elongated bends. It is another object of the present invention to provide a multiport drive shower that efficiently takes in water using a ram effect and delivers high volumes of cooling water to the outdrive. It is a further object of the present invention to provide a multiport drive shower that does not clog when encountering water-born debris. It is yet another object of the present invention to provide a multiport drive shower that effectively cools a multitude of heat producing locations along an outdrive.